What is a key characteristic of flexor muscles?

Flexor muscles are primarily responsible for decreasing the angle at a joint, which typically involves pulling limbs towards the body. When these muscles contract, they facilitate actions such as bending the elbow or the knee, allowing for movements that bring body parts closer together. For instance, when you flex your arm at the elbow, the biceps brachii muscle (one of the flexor muscles of the arm) shortens and pulls your forearm closer to your shoulder.

This action contrasts with the role of extensor muscles, which pull limbs away from the body and increase the joint angle, leading to extension. The other options mentioned do not accurately describe the primary role of flexor muscles. While stabilizing the core and joint rotation can involve muscle actions, they are not specific to the function of flexors. Thus, the correct choice emphasizes the essential function of flexors in bringing limbs closer to the body during various movements.